Continuous Integration (CI) in software development is the process of testing that a change in one place doesn’t break something else. Continuous Delivery (CD), on the other hand, is an extension to CI where every change in the code is also deployed. Both are and have been core parts in the advancements of Extreme Programming, i.e. rapid small-batch development. This, on its hand, has been the main contributor to advancements in rapid software development.